摘要:
A method for storing data across a plurality of N storage devices S1 . . . SN, wherein at least one of the storage devices has a storage capacity that not equal to a storage capacity of others of the storage devices involves identifying a storage device SMAX having a largest capacity of the plurality of storage devices S1 . . . SN; encoding the data with a erasure encoder to produce F erasure codewords, where F= ∑ K = 1 N F K with K being a counting integer; and distributing the erasure codewords among the N storage devices S1 . . . SN in approximate proportion to the storage capacity CK of each of the N storage devices S1 . . . SN subject to the constraint that enough erasure codewords are stored in each of the N storage devices to assure that if any one of the storage devices become unavailable, all of the data stored in the systems can be restored using the fountain codewords stored in the remaining storage devices S1 . . . SN. In accordance with certain embodiments consistent with the present invention, the erasure codewords are fountain codewords. This abstract is not to be considered limiting, since other embodiments may deviate from the features described in this abstract.
摘要翻译:一种用于在多个N个存储设备S 1上存储数据的方法。 。 。 其中存储设备中的至少一个具有不等于存储设备中的其他存储设备的存储容量的存储容量,包括识别存储设备的存储设备S MAX 多个存储设备S 1的最大容量。 。 。 N N; 使用擦除编码器对数据进行编码以产生F擦除码字,其中F =
摘要:
A technique maps the capacity of storage devices, such as disks, into any RAID group of a volume of a storage system regardless of the location of the RAID group within a volume block number (VBN) space of the volume. The technique separates disks and mapped VBN ranges, allowing for flexibility in the description and extension of RAID group capacities, while providing disk addition policies that support location-independent disk insertion into RAID groups. The technique also provides a disk label structure that supports the provision of multiple VBN ranges within a RAID group and within individual disks. Moreover, the technique provides file system support for allocation and topology management of the multiple mapped VBN ranges within disks and RAID groups, as well as noncontiguous VBN ranges across the RAID groups in the volume.
摘要:
A dynamically upgradeable fault-tolerant storage system permits a storage device to be replaced with a larger storage device. Data stored redundantly across multiple storage devices is reproduced on the replacement device, and the additional storage space on the replacement device is made available for redundantly storing additional data.
摘要:
Disclosed is an adaptive maximum request size process to change the maximum request size for a RAID system in order to reflect the highest possible maximum request size permitted by the RAID type and the physical drives included in the RAID system. The maximum request size is a primary limiting characteristic for physical drive and logical drive performance. The logical drive maximum request size is limited by the physical drive maximum request size. Physical drives supporting older revisions of the physical drive standards have a much lower maximum request size than physical drives supporting newer revisions of the physical drive standard. The adaptive maximum request size process permits a RAID system to adjust the maximum request size to reflect the highest possible maximum request size allowed for a given system based on the physical drives of the RAID system and the RAID types of all RAID logical drives. The adaptive maximum request size process also permits a RAID system to mix physical drives from older and newer generations while still achieving the highest possible maximum request size for the RAID system.
摘要:
The intelligent data storage manager functions to optimize the data storage utilization in a RAID data storage subsystem that is equipped with a heterogeneous mix of data storage elements. This is accomplished by using preference groups and biasing the writing of stripes of data in the redundancy groups of the RAID system to the disk drive or a set of disk drives in the preference group that have the greatest available data storage capacity. This ensures that the data storage capacity of the the disk drive with the largest available capacity is utilized to the maximum capacity. A preference group comprises a group of disk drives that is larger than the stripe size that is used to store data in a RAID format. The data storage manager does not write data across all of the disk drives in the preference group at a time, but rotates the collection of disk drives that are used to write a stripe of data. Therefore, if there is a failure of one of the disks in the RAID preference group, only a portion of the stripes stored therein need to be reconstructed, thereby speeding the reconstruction process. By including the the disk drive(s) with the largest available capacity in every stripe that is written to the preference group, the data storage capacity of the disk drive with the largest available capacity is preferentially used in the storage of data, thereby using this excess capacity first, with the utilization of the data storage capacity of this disk drive being related to the ratio of the preference group size to the RAID stripe size.